WHAT IS FLASH GLUCOSE MONITORING?
Flash Glucose Monitoring enables you to test your glucose levels without routine pricking your finger1. The small sensor automatically measures and continuously stores glucose readings day and night.
WHY IS IT DIFFERENT?
Unlike current blood glucose meters, the FreeStyle Libre sensor measures the glucose in the body's interstitial fluid.
WHAT'S THE DIFFERENCE BETWEEN BGM AND ISF?
Finger prick blood glucose readings and sensor glucose reading won't always match and in fact are likely to be different3. That's the interstitial fluid (ISF), a thin layer of fluid that surrounds the cells of the tissues below your skin, not from your blood. There is a 5 to 10 minute delay in ISF glucose response to changes in blood glucose. Glucose readings on ISF have been proven to reliably reflect glucose levels2.
IS IT ACCURATE?
The FreeStyle Libre system is accurate, stable and consistent over 14 days3 without the need for fingerprick calibrations.
To assess the accuracy of the FreeStyle Libre sensor, the glucose readings the sensor provides are compared to a known independent reference. In this case the reference is a finger prick blood glucose reading which is taken at the same time as the sensor scan. The comparison between the 2 different readings is plotted on a graph called a Consensus Error grid.
The closer the sensor reading to the reference blood glucose meter reading, the better the accuracy. This is reflected by the Consensus Error Grid by various areas on the graph labelled A to E. The higher the percentage of readings in Zones A and B, the more accurate the sensor is. The consensus Error Grid below shows 99.7% in Zone A and 99.0% in Zone B of the Consensus Error Grid3.
Image source: Bailey et al. The Performance and Usability of a Factory-Calibrated Flash Glucose Monitoring System. Diabetes Technology Therapeutics. Nov 2015: 17 (11)